Wooden gear-teeth



(Nd-Model.)

W. D. GRAY, R. BIRKHOLZ & E. REYNOLDS.

' WOODEN GEAR TEETH.

No. 376.522. Patented Jan. 17, 1888 I I UIINESSES JJVVEJVTOB m 02% mwftorney peratnre of about 212.

UNITED STATES PATENT OFFICE.

WILLIAM n. GRAY, RICHARD BIRKHOLZ, AND EDWIN REYNOLDS, on

- MILWAUKEE, wIsooNsIN.

WOOQDENIGEARQTEETH.

SPECIFICATION forming part of Letters Patent No. 376,522, dated January 17 1888.

' Application filed August 14, 1885. Serial No. 174,432. (No model.)

rim being broken away to show the mannerof inserting the cogs.

This invention relates to that class of cogwheels in which woodenteeth are inserted in a metallic wheel or. rim, and the aim ofthe invention is to so improve the teeth as .to prevent them from shrinking and becoming loose in the'sockets or mortises, to increase their wearing qualities, and to cause them to operate with a minimum degree of friction.

To this end the invention'consistsin a metal wheel or rim with wooden cogs or teeth charged or filled with paraffine.

Ithas for many years been the practice to insert wooden cogs into mortised rims or wheels, and it has alsobeen the practice, in order to reduce the friction, to coat the wooden teeth with lard, oil, or other fatty and oleaginous substances. Up to the present time, however,

no method of construction has been discovered by which the teeth could be caused to remain firmly in the wheel.

In the use of wheels as hitherto constructed great difficulty has been experienced by reason of the shrinking and loosening of the teeth, and because of the necessity of keeping them thoroughly lubricated to prevent wear. After many unsuccessful efforts to remedy the diffi culties mentioned, we have discovered that the desired results may be attained by simply charging, saturating, or filling the wooden teeth with paraffine at a sufficientlyhigh temperature to insure its incorporation therein.

In practice we find thata simple and efficient mode of treatment is that'of immersing the wood, either before or after the teeth are in finished form, in a bath of paraffine at a tem- The temperature may be modified; but care is to be exercised, on the one hand, to see that the temperature is sufficiently high and the paraffine sufficiently limpid to insure, its entrance deeply into the wood, and, on the other hand, that the temperature is not carried so high as to cause a burning or a material loss by vaporization. When the temperature is kept at about 212 Fahrenheit, the liquid parafline may be advantageously applied not only to seasoned wood, but to wood which is but partially seasoned, the paraffine serving in the latter case to expel the sap and take its place in the wood without cracking or checking the same. If the moisture be not wholly expelled by the paraffine, it will be retained and prevented from escaping by the surrounding envelope of paraffine, which completely seals the outer pores of the wood, so that no further shrinkage can occur.

In treating the wood it is recommended that it be heated previous to the immersion in the fluid to a temperature as high or higher than that of thefluid; but the same end may be accomplished if the wood be inserted without previous heating and permitted to remain in the parafiine until it has acquired a suitable temperature.

The application of the paraffine increases the weight of the wood to a considerable extent, imparts thereto greater hardness, and presents at all times asurface which will wear with slight friction.

While we do notclaim to be the first to saturate wooden teeth with lubricating materials, we do believe ourselves to be the first to discover and render available the peculiar properties and advantages herein stated.

Teeth treated in accordance with our invention are clearly distinguishable from those treated with materials other than paraffine and are possessed of marked advantages not to be found in teeth not hitherto known in the art. 7 Having thus described our invention, what we claim is- As a new article of manufacture, the gear having a metal body and wooden teeth charged or filled with paraffine.

In testimony whereof we hereunto set our hands in the presence of two attesting witnesses.

WILLIAM D. GRAY. RICHARD BIRKHOLZ. EDWIN REYNOLDS. Witnesses:

F. A. LARKIN, HANS BIRKHOLZ. 

